| 陆嫚嫚,马洁晨,张学胜,李玉成,王宁.MnOx负载生物质炭对Cu2+、Zn2+的吸附机理研究[J].农业环境科学学报,2018,37(10):2297-2303. |
| MnOx负载生物质炭对Cu2+、Zn2+的吸附机理研究 |
| The properties and mechanism of Cu2+ and Zn2+ sorption by MnOx-loaded biochar |
| 投稿时间：2017-12-07 |
| DOI：10.11654/jaes.2017-1684 |
| 中文关键词: 改性生物炭 高锰酸钾 铜 锌 吸附机理 |
| 英文关键词: modified biochar potassium permanganate Cu Zn sorption mechanism |
| 基金项目:国家自然科学基金项目（21275006） |
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| 摘要点击次数: 2183 |
| 全文下载次数: 1951 |
| 中文摘要: |
| 为研究MnOx负载稻秆生物炭对水溶液中Cu2+、Zn2+的吸附机理，以水稻秸秆为原料制备生物炭（RBC），并用不同浓度KMnO4溶液改性RBC制备MnOx负载生物炭（MRBC），在此基础上研究50% MRBC对Cu2+、Zn2+吸附动力学、等温吸附-解吸、pH和投加量对其吸附的影响，结合扫描电镜、红外光谱表征分析吸附机理。结果表明：改性稻秆生物炭表面负载MnOx，增大了吸附剂表面吸附位点，随KMnO4浓度升高能显著提高Cu2+、Zn2+吸附效果，50% MRBC对其吸附效果最佳；吸附动力学遵循准二级动力学模型，240 min基本达到吸附平衡；吸附等温线符合Langumir模型方程。50% MRBC吸附重金属的机理可能为：含氧官能团与重金属离子络合作用；金属离子与π电子发生阳离子-π作用；无机矿质元素（K、Ca、Mg等）与金属离子交换形成矿物晶体。 |
| 英文摘要: |
| Biochar has a large surface and may be used to adsorb heavy metals from aqueous solution. In this study, the properties and mechanism of Cu2+ and Zn2+ sorption from aqueous solution by MRBC (MnOx-loaded rice-straw-derived biochar) was investigated. Rice straw was used to produce biochar at a pyrolysis temperature of 600℃ for 3 h. In order to increase the Cu2+ and Zn2+ sorption capacity of the biochar derived from rice straw, MnOx-loaded biochar was prepared using raw biochar modified with potassium permanganate (KMnO4). In this work, the characteristics and mechanism of Cu2+ and Zn2+ sorption by 50% MRBC was studied. Batch sorption experiments showed that contact time, initial concentrations of Cu2+ and Zn2+, modified biochar dosage, and initial solution pH affected the removal of the heavy metals. The biochars before and after sorption were characterized using Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Results suggested that with an increase of KMnO4 concentrations, the MnOx-loaded biochar showed a better removal effect of Cu2+ and Zn2+, which could be attributed to the increase in sorption sites on the surface of the MnOx-loaded biochar owing to the presence of manganese oxides. The sorption kinetics fit the pseudo-second-order kinetics model, and sorption equilibrium was reached after 240 min. The sorption isotherm conformed to the Langmuir model, and the maximum sorption capacities of copper and zinc were 107.53 and 96.15 mg·g-1, respectively. The sorption mechanism was speculated as follows:(1) surface complexation between oxygen-containing functional groups and heavy metal ions, (2) the cationic-π effect of metal ions and π electrons, and (3) the mineral crystals formed by inorganic mineral elements exchange ions with metal ions in aqueous solutions. |
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